NASA’s Curiosity Rover has captured a blue sunset over the Martian skyline, demonstrating the icy blue color that descends on the Red Planet when night falls.
The images were captured by the rover’s MastCam in black and white on the 15th April 2015, but Damia Bouic from The Planetary Society was able to recreate their color.
These pictures came back to Earth in black and white, with a Bayer matrix. [Read this blog post for an explainer on Mastcam’s Bayer-filter images. -Ed.] I had to process them through GIMP with GMIC in order to rebuild the colors. A little processing in Pixelmator to remove these ugly white stripes due to overloaded pixels; a little bit of denoising to remove artifacts of the Bayer matrix, and voila: A blue Mars sunset!